Extracts of genitourinary (GU) malignant tissues (prostate, bladder, and kidney carcinoma) removed at surgery will be tested against the corresponding patient sera for immunological reactivity using modified counterimmunoelectrophoretic (CIEP) procedures to screen for those patients who show immunological reactivity to their own tumor extracts. Modified CIEP analyses will be carried out under defined conditions to detect free antibody in patient serum reactive with GU tumor antigen(s) and to permit concomitant detection of both specific antibody and the antigenic moiety released from immune complexes that may be present in patient serum. Monitoring sequential serum fluctuations of free antibody and of antibody specifically complexed during the course of disease progression will provide insight into the host-tumor relationship to establish a prognostic index and to assess the impact of therapeutic modalities. Sera which are reactive according to CIEP analyses and sera which can be rendered reactive by chemical dissociation of pre-existing antigen-antibody immune complexes will be analyzed by crossed, or two-dimensional, immunoelectrophoretic procedures: polyacrylamide (PAGE)-immunoelectrophoresis and isolectrofocusing (IEF)-immunoelectrophoresis. These two-dimensional procedures will allow the establishment of a consistent antigenic profile generated by the primary immune precipitation of GU antigens by antibodies in patient sera. Those patient sera that show a high specific immune complex titer will be subjected to chromatographic fractionations to isolate the reactive antibody component of immune complexes. This antibody population will then be retested by two-dimensional immunoelectrophoretic procedures; the pattern thus obtained will be compared to the antigenic profiles of GU malignancies generated by normally reactive patient sera. Such an approach will allow a determination of extent of overlap among prostate, bladder and kidney carcinoma antigens and to assess common antigen recognition by humoral antibodies in patient sera.